Imprint lithography processes are capable of forming structures that are 100 nanometers or less in size and have been used to manufacture devices that include, but are not limited to, microelectronic devices (e.g. integrated circuits), magnetic storage devices, mechanical systems, micro-electro-mechanical systems, optical devices and biological testing devices. Imprint lithography involves the formation of a relief pattern in material that is carried on the surface of a substrate. More specifically, in one type of imprint lithography process, a template with a relief pattern (or “mold”) is brought into contact with a material on a substrate that is in liquid form at room temperature, or that is liquefied by heating. The liquid material fills the template and assumes the shape of the relief pattern. The material is then subjected to conditions that cause the material to solidify and the patterned template is removed. A structure (or “layer”) in the shape of the relief pattern will then remain on the substrate. In order to facilitate removal, the patterned template may be coated with a release agent. This process may be repeated on different portions of the substrate with the same template in what is referred to as a step and repeat process. This process may also be repeated on the same portion(s) of the substrate with the same template to form multi-layer structures. Etching may be used to remove portions of the patterned material in some or all of the layers.
Although imprint lithography apparatus and methods have proven to be quite useful, especially in the area nanometer-sized structures, the present inventors have determined that they are susceptible to improvement. For example, the present inventors have determined that use of the imprint lithography apparatus and methods available heretofore can result in structural defects caused by liquid material residue and particles that can remain on the patterned template after removal, as well as by the degradation of the release agent coating on the patterned template.